I am the very proud owner of an 07’ Silverado Classic (DMax of course:D ) and its almost time for its second oil change. I first had my oil changed at 3,000 miles and now its getting close to 7000 miles (just FYI). I am planning on getting the transmission filter changed during this oil change but when I called and made the appointment the STEALLER told me that I would need to change the Differential fluid as well. I thought it would be a good idea until he quoted me a price of $150.00 to $160.00 just to change the fluid in the diff. DOES THIS MAKE ANY SENSE???
:rippedhan
This is my first diesel so I’m still learning how things work. If this is a normal price and if it needs to be done I have no problem paying that amount but I just thought I would check with the experts with this group and get your input.

Thanks in advance for any help.

doesnt make sense to me, check the book for intervals. i wouldnt pay anybody to change my oil or diff fluid though....well maybe 10 bucks if i can watch:)

I am assuming its easy to change the Diff fluid then. So what type of oil should i put in the Diff., i have always used royal purple but not sure what weight to use. How many quarts, and should i use Synthetic blend or not.

The rear takes full synthetic and the front can use dino. 2 qts front and 4 qts rear. I'm running RP in both the front and rear. I'm running 75W-140 but most people seem to run 75W-90. You may want to check your owners manual because I think the 07's may need synthetic in the front also.

I'd change the fluid in the rear yourself as well as the allison spin on. Really at that point your already lying on your back you may as well change them all yourself and save yourself a few bucks.

The tranny filter is simple unscrew it. Then clean the magnet that will most likely be attached to the filter with some brake kleen then fill the filter with some Dexron 6 from the stealer and good to go.

Rear differential is another very simple task there is a write up on it in the DIY section. Alot of people have found out that there rears were under filled from the factory. This was the case with mine it had maybe 2- 2.5 qts the rear takes almost 4. I put the chevy grape juice back in the rear end. I think it may have been a 15 mm wrench to take the vent/fill cap off and then I just used a 3/8 rachet with no attachment and just put it in the drain plug and turn. Again clean the magnet drain plug and reinstall and fill. Doesn't quite take 4 qts but is close.

Really up to you how you want to tackle it. If your are going to lay on your back to do one might as well do them all. If you do it yourself look up a vendor on here and get the stuff thru them. A spin on tranny filter thru the dealer is like 46 bucks the grape juice is expensive also.

Good luck with it but all that stuff can be done in an hours time.

Mobil 1 syn 75W90 in both diffs on my truck.

do i need to change the fluid in the front differential and if so how hard is it to do. i found how to change the back diff. in the DIY section but i am having trouble locating a thread for changing the front diff fluid??

change both...front is just like the front..drain plug on bottom & fill plug on the side.

I run Schaeffer's 75/90 synthetic with moly--it just doesn't get any more slippery or better--oldest oil co. in the U.S. of A.

Mobil 1 syn 75W90 in both diffs on my truck.

Same here. For the rear it makes life easier if you take the spare out. Then you can sit under there. Front just take the skid plate out and if you want the LF tire off.

The new owners manual for my 07.5 LMM tells me to use synthetic 75w90 in the rear end and use a special GM fluid in the front transfer case. I see most guys are using the same fluid in the rear end and the transfer case. Can I feel comfortable in using Mobil 1 in both or do I have to get ripped off at the staeler for some special transfer case fluid?

the stealler quoted me a price of $23.00 per quart of there synthetic stuff (over priced i'm sure). so i went to the local parts store and spent a good 30 min. comparing different synthetic blends. I, personally, narrowed it down to 2 main brands Mobil 1 and Royal Purple. I opted to go with the Royal Purple because, from what i can tell, it breaks down at a higher temp. and it says something about water seperation, which i'm sure they all do. also GM told me that Royal Purple was compatible with the Locking Diff. from what i understand you can use the same fluid in both the front and rear.....I'm still new at this and still learning so if anyone has any input that would be great:D

Both ends are easy without removing tires. Ramps make life a lot easier. This little valve will help a ton. Once attached to the bottle, inverted with the hose in the differential poke a little hole in the bottle. (the end that is up) This has worked well me me. Later! Frank

The new owners manual for my 07.5 LMM tells me to use synthetic 75w90 in the rear end and use a special GM fluid in the front transfer case. I see most guys are using the same fluid in the rear end and the transfer case. Can I feel comfortable in using Mobil 1 in both or do I have to get ripped off at the staeler for some special transfer case fluid?

Dont use gear lube in the transfer case, only the difs. The transfer case should have atf or the 5w 30 syn oil.